..I - 

FOREST RESEARCH NOTE

NORTHEASTERN FOREST EXPERIMENT STATION 

Upper Darby, Pennsylvania 

No, 63 

December 1956 

Estimating Costs Of Improving Adirondack Timber Stands 

By Killing Culls With Frills And Sodium Arsenite 

Although it has been known for many years that sodium 

a arsenite solution applied in ax frills is an effective means 

of killing cull trees () no published information could be 

found on the cost of stand-improvement work with this method 

under Adirondack conditions. 

Since 1951 sodium arsenite solution has been used in 

frills to improve timber stands on the Paul Smith hperimental Forest. These were natural mixed stands, varying 

from old growth to stands recently cut, and typical of conditions in this region. The trees treated were unmerchantable hardwoods, 

The method used for this work consisted of an application of sodium arsenite solution to an ax frill. The frill 

consisted of a single line of overlapping ax cuts, encircling the tree and extending slightly into the sapwood. When 

a the arse~te solution (28-40 percent) was applied during the 

sap-peeling season, trees generally died within a short 

tim'e; this treatment also caused bark to peel within 1 year 

(2) 

The crew generally consisted of two amen and one 

other man to apply the poison. Trees 6 inches d.b.h. and 

larger were frilled, but smaller trees received single ax 

cuts spaced about 4 inches apart around the tree. Each axman selected and tallied the trees he frilled. 

Costs, in terms of man-hours and quantity of poison, 

may be estimated on the basis of average size and number of 

trees treated per acre, or on the basis of basal area 

treated per acre (table 1). These relationships may be useful to others in making preliminary estimates of the cost of 

doing similar stand-improvement work. Actual costs on 

similar operations will.var-y depending upon crew experience 

and efficiency, amount of slash and underbrush, terrain, and 

1 

k 
Table 1.--Details of timber stand improvement work with frill and sodium arsenite solution 

l~ata given only for battery-filler syringe application. 

Compartment 

no. 

whether trees to be treated have been marked or must be selected by the amen. 

Labor Cost 

Acres Inches Inches No. Sq. ft. Man-hrs. Gallons 

14 30 6.4 1.0 94 2 5 4.12 -- 

Area 

treated 

An estimate of the man-hours of labor required for 

timber-stand improvement work may be obtained from the regression formula (fig. 1) : 

No. trees 

Man-h0urs1 per acre - Cuerage) d.b.h. (treated ) (0.00~)) + 0.9 

per acre 

Average 

d.b.h. of 

trees treated 

In terms of basal area (a somewhat less consistent measure), 

the average production rate was approximately 83 square feet 

per man-hour. The range was from 6.1 to 11.8 square feet. 

Amount Of Poison Used 

The sodium arsenite solution was applied to the 

frills either with a paintbrush or with a battery filler 

syringe fitted with a metal tip (1/16-inch orifice). The 

latter is preferred, since it markedly reduces the hazards 

resulting fmm spillage and spattering, and also requires 

considerably less poison. 

poison1 

used 

(~er acre) 

Minimum 

d.b.h. 

treated 

ltlMan-hourslt includes all time spent on the work area 

except the lunch period. It does not include travel time to 

and from the area. 

(per acre) 

Trees 

treated 

(per acre) 

Basal area 

treated 

(per acre) 
In using the battery-filler syringe, the quantity of 

sodium arsenite solution required per acre may be estimated 

from the regression formula: 

No. trees 

= (,.:;::) ( treated ) (0. i05) 

per acre per acre 

In terms of basal area, 1 gallon was sufficient to 

treat an average of 110 square feet, with a range of 90 to 

125 square feet. 

Because sodium arsenite is poisonous to man and animals, reasonable care must be taken in using it. The safety 

precautions followed at the Adirondack Research Center have 

been outlined in a previous publication by Rushmore (2) 

I I REGRESS ION LINE FITTED TO PLOTTED DATA BY METHOD OF LEAST SQUARES. I 

I 0 - 100 200 300 400 500 600 7 00 8 00 

PRODUCT OF: (AVERAGE D.B.H. OF TREATED TREES) X (AVERAGE NUMBER OF TREATED TREES PER ACRE) 

Figure 1.--Curve for estimating labor requirement for 

killing cull trees with frills and sodium arsenite. 

PlotteG points are actual man-hour requirements, by 

compartments. The standard error of estimate is 

+ 0.72 man-hours. 
Literature Cited 

(1) MacKinney, A. L., and Korstian, C. Fe 

1932. Felling, girdling, and poisoning undesirable 

trees in forest stands. Jour. Forestry 30: 

169-177. 

(2) Rushmore, Francis M. 

1956. The frill: a new technique in chemical debarking. Jour. Forestry 54: 329-331. 

--ROBERT 0. CURTIS 2 

Northeastern Forest Experiment Station 

Forest Service, U.S. Dept. Agriculture 

2~tationed at the Adirondack Research Center, which 

is maintained by the U. S. Forest Service in cooperation 

with Paul Smith's College, Paul Smiths, N. Y. 

AGR [CULTURE-FOREST SERV ICE.-UPPER DARBY